X-irradiation

However, it was recently shown that the ability of Escherichia coli (Harrington, 1964, 1966) and of calf thymus (Zimmermann et al., 1964, 1965) DNA's to prime in vitro RNA synthesis is severely depressed by X-irradiations.

The first gene shown to be involved in a cell cycle checkpoint was originally recovered because of its sensitivity to X-irradiation (6).

Bardeen and Baetjer (1904) used X-irradiation (without stating doses) on Dugesia tigrina (maculata) and D. lugubris.

Administration of olive oil within an hour after whole-body x-irradiation of male mice at a dose of 625 r (LD50 (30)) significantly increases the survival rate when compared with the x-irradiated untreated mice.

In a subsequent breeding trial, they bred three groups of 8 mares with semen from one stallion that had been exposed to x-irradiation doses of 0, 1.0, or 10.0 μSv; an entire ejaculate was irradiated and inseminated into each mare once during estrus within 48 hours before ovulation.

In laboratory rats also, intensive, localized x-irradiation of the bowel have been reported to induce intestinal carcinomas (37).